Base: Add default "ShowScrollBar" value to Terminal.ini config

Author: https://github.com/bgianfo
Commit: https://github.com/SerenityOS/serenity/commit/1678dcbf91a
Pull-request: https://github.com/SerenityOS/serenity/pull/11904
Reviewed-by: https://github.com/Quaker762 ✅
Reviewed-by: https://github.com/elyse0 ✅

Base/home/anon/.config/Terminal.ini

@@ -1,6 +1,7 @@
 [Startup]
 Command=
 [Terminal]
+ShowScrollBar=true
 MaxHistorySize=1024
 [Window]
 Opacity=255